fixes whitespace error for union generation (#714)

Author: bashbaug

scripts/generator.py

@@ -942,7 +942,7 @@ def makeCParamDecl(self, param, aligncol):
 
         # If prefix was originally non-empty and the param has no elements
         # (e.g. is nothing but text), preserve it.
-        paramdecl = prefix + paramdecl
+        paramdecl = paramdecl + prefix
 
         if aligncol == 0:
             # Squeeze out multiple spaces other than the indentation